Fate-of-capsid assay. MDTF or D17 cells expressing TRIM5αrh or TRIMCyp and control cells were infected with HIV-1 VLPs for 4 hours, then cells were allowed to grow for 2 more hours in a virus-free medium. Following the infection, cells were submitted to hypotonic lysis and the protein suspension was sedimented through a 50% sucrose gradient. HIV-1 CA was detected by western blotting of whole lysates, post-sedimentation pellets and supernatants (materials that did not enter the sucrose cushion). The mature CA (24 kDa) band was quantitated for the blot showing the pellet fractions and quantitation data are shown expressed as relative values.